Regex Tester
Test and fine-tune your regular expressions with live visual highlighting. Inspect capturing groups and error messages in real-time.
Debugging Patterns with Regex Testers
Regular expressions (regex) are incredibly powerful tools for pattern matching, data extraction, validation, and string replacements. However, because regex syntax can be dense and complex, writing a working pattern often requires trial and error.
Our online regex tester provides immediate visual feedback. By highlighting matching substrings directly within the test input, it allows you to verify boundary cases, capture groups, and case-sensitivity settings in seconds.
Frequently Asked Questions
What regex flavors are supported?
This tester uses your browser's native JavaScript RegExp engine. It fully supports standard JS regex expressions, flags, capturing groups, and modern lookaround patterns.
How does real-time match highlighting work?
As you edit your regular expression pattern or flags, the tool recompiles the regex in the background and scans your test text, highlighting any matches.
Is my text data private?
Absolutely. All scanning and matching code executes directly inside your browser. No strings or regex scripts are sent to any server.